Process for manufacturing of polyisobutene succinic anhydrides

Abstract

A process manufactures polyisobutene succinic anhydrides from certain polyisobutene mixtures by reacting highly reactive polyisobutene with content of alphadouble bonds of at least 50 mol % and maleic anhydride in a stoichiometric molar ratio of 0.6 mole of maleic anhydride:1 mole of polyisobutene or higher at a temperature of 150 to 260° C. for 15 minutes up to 10 hours.

1 . A process for the preparation of polyisobutene succinic anhydrides, comprising:
 reacting highly reactive polyisobutene with a content of alpha-double bonds of at least 50 mol % (determined by 1H NMR spectroscopy) and maleic anhydride in a stoichiometric molar ratio of 0.6 mole of maleic anhydride:1 mole of polyisobutene or higher at a temperature of 150 to 260° C. for 15 minutes up to 10 hours,   wherein the highly reactive polyisobutene has a content of one or more ethers of the formula PIB—O—R 1  of at least 0.01 wt % and less than 0.8% by weight, determined by 1H NMR spectroscopy,   in which PIB represents a residue derived from polyisobutene and R 1  is C 1 - to C 10 -alkyl.   
     
     
         2 . The process according to  claim 1 , wherein the highly reactive polyisobutene has a content of alpha-double bonds of at least 60 mol %. 
     
     
         3 . The process according to  claim 1 , wherein the highly reactive polyisobutene has a content of alpha-double bonds of at least 70 mol %. 
     
     
         4 . The process according to  claim 1 , wherein the maleic anhydride is applied in a molar ratio of 1 or more per 1 mole of the polyisobutene. 
     
     
         5 . The process according to  claim 1 , wherein the maleic anhydride is applied in a molar ratio of 1.2 to 3 per 1 mole of the polyisobutene. 
     
     
         6 . The process according to  claim 1 , wherein the reaction temperature is from 175° C. to 250° C. 
     
     
         7 . The process according to  claim 1 , wherein the reaction is carried out under an inert atmosphere. 
     
     
         8 . The process according to  claim 1 , wherein the reaction is carried out in the absence of a solvent. 
     
     
         9 . The process according to  claim 1 , further comprising:
 polymerising an isobutene-containing reaction mixture in the presence of at least one Lewis-acid in the presence of at least one alkanol R 1 OH under reaction conditions so that a polyisobutene is obtained with a content of ethers of the formula PIB—O—R 1  of at least 0.01 wt % and less than 0.8% by weight,   separating unreacted ingredients of the reaction mixture from the polyisobutene-containing product, and   reacting the thus obtained ether-containing polyisobutene with maleic anhydride.   
     
     
         10 . The process according to  claim 9 , wherein the Lewis-acid is selected from the group consisting of boron halides, aluminium halides, alkyl aluminium halides, and iron halides. 
     
     
         11 . The process according to  claim 9 , wherein the alkanol R 1 OH is selected from the group consisting of methanol, ethanol, iso-propanol, sec-butanol, tert.-butanol and mixtures thereof. 
     
     
         12 . The process according to  claim 9 , wherein the polymerisation is carried out in a molar ratio of alkanol R 1 OH:Lewis-acid of 1 to 2:1. 
     
     
         13 . The process according to  claim 9 , wherein the polymerisation is carried out in a molar ratio of alkanol R 1 OH:isobutene of 0.00025 to 0.0025:1. 
     
     
         14 . A mixture, comprising:
 a major amount of highly reactive polyisobutene with a content of alpha-double bonds of at least 50 mol % and a minor amount of one or more ethers of the formula PIB—O—R 1 , in which PIB represents a polyisobutene-residue and R 1  is C 1 - to C 10 -alkyl,   wherein a content of ethers is at least 0.01 wt % and less than 0.8% by weight.   
     
     
         15 . The mixture according to  claim 14 , wherein R 1  is C 1 - to C 4 -alkyl. 
     
     
         16 . The mixture according to  claim 14 , wherein the content of ethers is from 0.05 to 0.75% by weight. 
     
     
         17 . A method for the preparation of a polyisobutene succinic anhydride, the method comprising:
 reacting the mixture according to  claim 14  with maleic anhydride.   
     
     
         18 . The mixture according to  claim 15 , wherein R 1  is selected from the group consisting of methyl, ethyl, n-butyl, secondary-butyl, and tert.-butyl.